As a consequence of recent technical developments, various types of personal computers (PC), such as desktop, tower and notebook types, are being manufactured and sold. The notebook PCs that are produced are compact and light, and are designed while taking into consideration their use in a mobile environment, i.e., their portability and suitability for outdoor use.
FIG. 10 is a specific diagram illustrating a notebook PC. A notebook PC 1 has a so-called "clam shell structure" constituted by a PC main body 2, which incorporates a system board and external storage devices (e.g., a hard disk drive, HDD, and a floppy disk drive, FDD), and a lid 3, which is pivotally hinged at the rear edge of the main body 2. A keyboard unit 13 is mounted on the upper face of the main body 2, and a liquid crystal display (LCD) unit 18 is provided inside the lid 3. When the PC 1 is not used or is to be carried, the lid 3 is closed so that the keyboard unit 13 and the LCD unit 18 are protected by a strong case.
One of the features of a notebook PC is "battery operation," for which power is supplied by an incorporated battery. This feature is provided so that the PC can be used outdoors, for business trips, or on other occasions when an AC power source is not readily available. The incorporated battery is generally a "battery pack," which is a package containing a plurality of battery cells. For such battery packs, rechargeable battery cells, such as Li-Ion cells or NiMH cells, are employed.
A battery pack 15 is usually flat, and is placed in a special storage space within the main body 2 of the notebook PC 1. For a PC model, such as the "IBM ThinkPad 760" ("ThinkPad" is a trademark of IBM Corp.), a notebook PC sold by IBM Japan, Ltd., the keyboard unit 13 can be opened and closed relative to the main body 2 of the PC 1 to access a battery 15 held in a battery compartment 14 (see FIG. 11).
For a PC model such as the "IBM ThinkPad 560," also sold by IBM Japan, Ltd., that has a keyboard unit 13 that can not be opened, a shallow battery compartment 16 is recessed in the bottom of a main body 2 of a PC 1. A battery pack 17 can be inserted through an opening formed in the face of the front wall of the main body 2 (see FIG. 12), and by manipulating a slide knob 6, which is provided at the periphery of the battery compartment 16, the battery pack 17 can be securely locked in place by a holding mechanism (not shown). When the slide knob 6 is slid in the direction opposite to the locking direction, the battery pack 17 is released from the locked state to permit its removal and replacement. In this case, portions of the side walls of the battery pack 17 are exposed, even when the pack 17 is inserted into the main body 2, and constitute parts of the main body 2 of the notebook PC 1.
Packaged in each of the battery packs 15 and 17 for the notebook PCs 1 are ten battery cells, sufficient to provide the several hours of operation. In other words, the weight of each of the battery packs 15 and 17 is several tenths that of a corresponding notebook PC 1, and the energy density per volume/capacity is very high. The battery packs 15 and 17 must therefore be carefully handled. When a battery pack 15 or 17 is dropped, not only can its cover be damaged and a user injured, but also a short-circuit between terminals will occur as the result of entry of a foreign metal substance, resulting in ignition and explosion. When a notebook PC is designed, therefore, one of the important design considerations is how to securely fix the battery pack 15 or 17 in the battery compartment.
For the above described notebook PC that has a keyboard unit 13 that can be opened (e.g., the "IBM ThinkPad 760"), the problem concerning the dropping of the battery pack 15 can be easily resolved by securely fixing the keyboard unit 13 to the main body 2. For the model wherein the battery compartment 16 is recessed in the bottom of the main body 2 of the notebook PC 1, this problem is not easily resolved. This is because: the opening of the battery compartment 16 is directed downward, i.e., in the direction in which the battery pack 17 may fall; the slide knob 6 for unlocking the battery pack 17 is exposed on the bottom surface; and the portions of the side walls of the battery pack 17 constitute parts of the main body 2 of the notebook PC 1 and are easily affected by an impact.
When, for example, a user is carrying the notebook PC 1, and he or she inadvertently displaces the slide knob with one of the fingers holding the main body 2 of the PC 1, the battery pack 17 may fall off. Since the slide knob 6 slides along the bottom face of the main body 2, such an accident can easily occur.
Further, when the notebook PC is being removed from a bag, the slide knob 6 can be displaced by catching on one of the objects surrounding it.
In addition, if the notebook PC is being used but the user forgot to lock in the battery pack 17, the battery pack 17 may fall when the main body 2 is lifted.
It would be relatively easy for one having ordinary skill in the art to envision a double locking system wherein a locking mechanism, for inhibiting the movement of the slide knob 6, is separately attached in order to ensure that the battery pack 17 is securely held. The structure of the locking mechanism in this case could provide for a bar (not shown) to be inserted in the direction in which the slide knob 6 moves. Since a dual operation, such as the release/holding of the battery pack 17 and the unlocking/locking of the slide knob 6, would be required to replace the battery pack 17, for a user, employing this structure would not be easy.
Were a user to forget that attachment/detachment was inhibited by the holding mechanism and the locking mechanism, and try to force the battery pack into the battery compartment 16, peripheral components around the battery compartment 16 would be damaged.
It is therefore one object of the present invention to provide a superior battery attaching mechanism, for portable computers, in which a battery compartment is recessed in the face of a wall of a computer.
It is another object of the present invention to provide a battery attaching mechanism for portable computers with which a battery can be safely stored and secured, and yet can be easily removed by performing a simple operation.
It is an additional object of the present invention to provide a battery attaching mechanism, for portable computers, with which, even when a battery holding state or a battery locked state exists in the computer, a battery pack can be accommodated without causing damage to a holding mechanism and a locking mechanism.